Why Surveyor Concern About Accuracy & Precision - Part 1

observations are never exact and will always contains errors. High tech instrumentation only can reduce error size or also the proper procedure only make sure the the errors to within tolerable limits.

Theory of Errors in Observation - Introduction

Making observation or doing measurements and subsequent computation & analysis using them are fundamental task of surveyor. We surveyor must be good observation skill & high tech mechanical equipment to get good measurement. But no matter how good and carefully the observation made, observation are never exact and will always contain errors.

Surveyor must have a knowledge to understand the different kind of errors, their source and expected magnitudes under varying conditions and their manner of propagation.

For more technical,

"surveyor are usually faced with the problem of estimating some unknown quantities (parameter). This is done through collecting several measurement of some kind known as observation - and then adopting the appropriate mathematical model relating both observation an0d unknowns."

ERROR: difference between observation of quantity and the true value (which can never be known)

true error (E) = observed value (l) - true value (t)

since true value (t) can never be known, true error (E) will never be known as well.

Errors in observation occur from several sources such as

1. Personal - Limitation of the observer - the ability to repeat the same measurement - carelessness of the observer

2. Instrumental - due to imperfect construction

3. Natural - Due to changing environmental condition in which the measurement are made.